At the end, Lee Jihyeon 9p gives an ambiguous opinion.
Q. Which do is better to do, a few hard problems or many easy problems?
A. I’d recommend doing hard ones if you’re able to. For amateur players, it’s more effective to do easy problems in a limited time. If that’s difficult, you don’t need to do a lot of tsumego. All you gotta do is just do it consistently. Doing a lot of them would be better though.
The channel is Cho’s Go. It looks good, though it’s a shame it was apparently only active from February to June of last year.